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 Replies: 11 / Views: 2,020 |
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Pillar of the Community
Canada
1081 Posts |
Hello Coinland - Can someone tell me what the green stuff is on this coin? I'm guessing that this is a copper coin and that it's therefore copper oxide. I'm wondering if this should be a deal-breaker for purchase? The seller lists this as XF - which seems within ballpark for me though I'm concerned about the surfaces....   |
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Pillar of the Community
United States
5825 Posts |
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Rest in Peace
United States
18456 Posts |
Verdigris and or corrosion . Looks like a nice old coin with a great design . If the price from the seller is right , you might want to send it to NGC for conservation .  |
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Bedrock of the Community
Australia
21786 Posts |
Google Images:
'Coins from the wreck of the Admiral Gardner'
British East india Company Bronze coins from this wreck were recovered in their thousands.
Interestingly, a lot of them survived with almost no evidence of seawater corrosion on them at all!
I have seen three denominations:
V CASH, X CASH and XX CASH.
An interesting piece of numismatic history hardware, with a shipwreck provenance.
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Pillar of the Community
 Canada
1081 Posts |
Thanks folks - hadn't thought of any of that. There's a fair number of these on ebay but the green schmutz threw me. |
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Pillar of the Community
 United States
7933 Posts |
Carbonate, not oxide.  And I bet this coin looks nicer in hand than the photos show. Edited by tdziemia
05/27/2020 9:40 pm
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Bedrock of the Community
Canada
24885 Posts |
Edited by Dorado
05/27/2020 10:38 pm
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Bedrock of the Community
Australia
21786 Posts |
To be more exact, verdigris is a variable combination of
copper hydroxycarbonate and copper hydroxychloride.
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Pillar of the Community
Canada
1081 Posts |
@sel_69l - thanks! I clearly need to read up on my transition element chemistry!
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Bedrock of the Community
Australia
21786 Posts |
@Silver101:
Forgive me, perhaps I was being a bit too pompous.
I have been looking around on line metal for detecting sites and the cleaning of coins recovered from burial, and in particular, bronze coins that have been affected by verdigris.
Some of the methods I have looked at are well worth further investigation. No doubt museums are familiar with some of the procedures that I have found.
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Bedrock of the Community
United States
20753 Posts |
IF the price is low enough, might be worth a little bit of money using miscellaneous products to clean off that green.
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Pillar of the Community
United States
992 Posts |
I use VERDI-CARE on some coins. stops the process from continuing.
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Replies: 11 / Views: 2,020 |
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Posted 05/27/2020 08:44 am
